The Ace Combat series are my personal favourite games. This is a bit of an anomaly, as I generally prefer RPGs (of various kinds from 'shooter with mild RPG elements' through to 'classic turn based') and open world action (other favourites would be things like Planescape Torment, ME2, AC:Black Flag, Prey, Lost Odyssey, DA:Inquisition, Dead Space series, Bioshock series, GTA:SA etc). I just find the classic AC game mechanics and presentation very compelling, and it's one of the few games I am happy to play in short bursts as well as binges. The Ace Combat series had a surprising amount of representation on these forums as well; several entries in the 'SDN Nations' STGOD series had people reusing setting elements in their nation designs, and the classic HAB (Heavy Armor Brigade) threads had a few references to the AC superweapons as well. This is because the 'Strangereal' setting for most of the AC games was bizarrely detailed and deep for essentially an arcade flight game with a light military sim veneer; clearly the alternate-Earth, near-future sci-fi elements were appreciated by a lot of people.

Prior to the latest release, I would rank the games like this (I have 100% completion on all of these, some of them more than once, but have never been interested in the multiplayer):

Ace Combat 5 (2004, PS2) : The all-time best, by a significant margin. The most important reason is the mission design: it has the most variety in mechanics and pacing, as well as the highest number of missions (including the only multiple paths other than AC3; and that's not even counting the bonus mini-campaign) and aircraft. Art design is excellent: are numerous iconic enemies, structures and aircraft including an SSTO, giant submersible carriers, a kill sat, a mass driver launch system, a Bavarian-style castle, a giant cold war fortress and the Falken as a flyable super-fighter. The elite enemies are fairly numerous and individually not too hard, so they aren't frustrating to fight. The allied characters are generally likeable and you genuinely do feel like you are commanding a flight (squad) of aircraft; your wingmen shoot down enough enemies to be useful and add plausibility but not enough to kill-steal, you can give them various commands that do make a difference when going for maximum mission rank, when you lose them to enemy fire it is actually quite moving. The plot is essentially alt-America and alt-Russia circa 2010 sans nuclear weapons go for a full on hot-war, your squadron goes from rookies to aces, is betrayed by your own side, find out that the war was orchestrated by the remnants of alt-Nazi-Germany who have sleeper agents everywhere, rescue the president of alt-America, and defeat all the ex-Nazi agents and their stolen superweapons. This manages to feel relatively plausible, as there is sensible foreshadowing and the high mission count gives the plot twists enough time to play out properly; the enemy also react relatively realistically to your implausible kill counts, which is funny to listen to. The main enemy superweapon is 'occassionally you have to dash to a higher altitude', which is fortunately not overused; there are some 'you must fly at low altitude' missions as well, justified by radar coverage. The player unlockable superweapon is the Tactical Laser, which is amusingly overpowered but still requires some practice to master (since it has no auto-tracking). Finally, the music is amazing, numerous standout tracks.

Ace Combat 4 (2001, PS2) : Launched the modern AC series, similar but simpler than AC5 in all areas (graphics, flight model, AI, mechanics). Somewhat more realistic plot: a straightforward military campaign of 'fascists take over country which proceeds to conquer neighbours, international coalition must beat it back'; no characters whining about how horrible war is or how they want to frag their commanders. No squad to command, allies are purely decorative. Flight model and enemy AI are a bit simpler, on the plus side this is the only game in the series that has realistic ceilings and a couple of missions that take you up to high altitudes. The plot is narrated still frames instead of CGI cutscenes, focusing on a personal rivalry with an enemy ace. Some excellent tracks in the soundtrack although not quite as many as AC5. This game has the most 'long mission with no special gimmicks or events where you systematically destroy every enemy target in the theatre', which are quite relaxing to play as one-off sessions. The final mission is arguably the best paced climax in the series. The main enemy superweapon is 'occasionally you must dash to a low altitude and stay there for a few seconds'; the actual installation (of eight railguns) is satisfying to destroy as well. There is only one fictional superplane, but it's the most iconic one in the series (the X-02). The player-unlockable superweapon is the quick-maneuver missiles (with omniscient 360-degree tracking for this game only) which don't require much skill but are limited quantity and quite funny to take out the enemy aces with (in the sense that Indiana Jones deciding to just shoot the bad guy instead of engaging in a sword fight was amusing). I would say that the biggest drawback for this game was the simple flight model and AI meant that there is not much point trying to pull complex maneuvers, and it does tend to degenerate into chasing the HUD target pointer more often than later games. This is the game that introduced me to the series.

Ace Combat 6 (2007, Xbox360) : A significant graphical improvement, most noticeably the draw distance. General plot is similar to AC4 : one nation is taken over by fascists and invades a second nation, which is nearly wiped out, has to come back from the brink'; slightly less plausible as there is no (apparent) international support. Flight mechanics and enemy AI were slightly improved over the PS2 games as well; you have to lead targets more realistically, scissors, Immelman etc are more relevant, and more video-gamey 'high-G turns' were added which let you trade speed and risk of stalling for a faster turn to get an enemy into view. Overall mission variety and length similar to AC4 but with better ground troop interaction similar to AC5 but on a larger scale, i.e. it feels more like participating in a real battle with front lines that evolve over time. Simplified wingman commands and only one wingman, but this was the only game with the 'allied support' mechanism where if you took out the enemies attacking friendly units, you could later call on their support to attack tough enemies in the final phase of the mission. This generally worked well and was quite satisfying. Overall sound design was slightly improved over the PS2 games, decent music on a par with AC4 if somewhat overusing the main theme. The flotilla of flying battleships were iconic and fun to take down, the final mission superweapon somewhat less so (plays as a more annoying version of Megalith from AC4). The enemy superweapon attack gimmick is 'impact markers appear on the map, you must avoid them for 10 seconds' which is a bit annoying when you are trying to dogfight. There is one fictional superplane as per AC4 which is more 'balanced' in the sense that it's supermaneuverable but stalls very easily, forgettable design. The unlockable player superweapon is Macross-style kill-12-targets-at-once high-damage tight-tracking multi-missiles. This is somewhat fun but turns most missions into 'how quickly can you target everything' and makes S-rank a bit too easy even on Ace difficultly. This was the first game with meaningful DLC, consisting of a handful of missions remade with a lot more targets to shoot at (out of continuity). The major drawbacks with this game were: annoying cringeworthy character dialogue (particularly but not exclusively in cutscenes), and a handful of really annoying, frustrating missions involving supermaneuverable UAVs. Essentially these things zip around pseudo-randomly at ridiculous speeds and either nibble at you with machine guns or summon cruise missiles to their location and then be miraculously unharmed by the resulting tacnuke-scale explosion. Hitting them, particularly on the later mission where they are support for an enemy ace, is purely a matter of luck and rather tedious as you keep lining up decent shots which they almost teleport out of the way of.

Ace Combat 3 (1999) : This was really stretching what was possible to cram into the PS1. Explicitly sci-fi/futuristic setting, 52 (!) missions albeit only a fraction relevant in any one playthrough, dozens of fictional aircraft and some classic ones, high-concept plot, experimental game mechanics including a space-based mission. The first time I played this it was the European version (on PS2 backward compatibility mode); the Japanese version (on emulation) is substantially better. Still a lot more like an arcade game than the later AC style (e.g. there is an announcer that calls out all your kills) but less so than AC2. Honestly like most PS1 games playing this feels like archeology now, the low res and truly horrible draw distance are hard to tolerate, but there are lots of interesting and unique elements to appreciate.

Ace Combat Zero (2006, PS2) : Ace Combat Zero goes back to the alt-mid 90s when alt-Nazi-Germany was defeated by another international coalition, this time explicitly headed by alt-United States. A somewhat darker plot than usual with nuclear weapon use and many of the troops breaking off to form an archist organisation that try to start a general nuclear war, which you have to defeat in the last few missions. I think the main focus of the Project Aces dev team at this time was AC6, and this game was put out on a lower budget to squeeze some final revenue out of the AC4/5 engine and art assets. This does show in sparser and simpler mission designs and cutscenes. The focus of the game is more on air-to-air and defeating a larger roster of named enemies than AC4/5; the enemy AI is perhaps a little better than 5 but not really enough to carry this. There is enemy superweapon arc; just one mission where you take out a ground-based laser with unique mechanic, and one where you fight a much smaller simpler prototype for the AC6 flying battleships. The player-unlockable superweapon is a missile with a huge explosion (i.e. an AIM-26A) which the enemy aces usually dodge but is somewhat useful for destroying fighter formations in the furball missions. Music is pretty good a little behind AC4/5 level. The whole game has a slightly depressing, budget feel although on the plus side the final mission is probably the best one-on-one enemy ace dogfight in the series; the enemy has several semi-plausible tricks without resorting to just 'takes lots of hits' or 'can magically dodge everything' and the associated music matches perfectly.

Ace Combat Assault Horizon (2011, PS3/Xbox360) : An attempt to do something a bit different, set in the real world (almost), with missions that have substantially different mechanics: flying attack helicopters, controlling the weapons on an AC-130 gunship, briefly piloting bombers, flares to add variety to missile evasion. I really appreciated the mechanical variety, even if it was a bit rough, and the soundtrack was decent too (more rock/metal than the usual AC orchestral style, but that fits the tone). Unfortunately the core fighter aircraft mechanics were completely broken, which rendered all of that moot. In an attempt to make the game more 'accessible', fighter combat mostly works by maneuvering into the rough vicinity of the enemy, at which point you get locked into a predetermined 'pipe' where the scenery scrolls by automatically, the camera rolls around drunkenly, and your input is limited to jinking around a bit and press a button combo to switch to chasing the enemy (if you are in front) or to avoid the enemy getting behind you. Of course this is very repetitive, destroys all creativity and player agency, sucks most of the skill and fun away and gets boring a few missions in. The visual design focuses on looking like an action movie with enforced close fly-bys of real landmarks and exploding industrial complexes, and ridiculously overwrough close-ups on downed enemies. This was during the 'gritty brown desaturation' era of video games so unsurprisingly everything is washed out, and the low texture resolution of the 7th gen consoles is rather obvious in the constant close-ups (to be fair, there is a PC version which probably fixes this issue at least). Unlike all the above games I've never wanted to replay this one.

Ace Combat 2 (1997, PS1) : The original prototype, mechanically very close to the Air Combat arcade game. (Understandably) horrible PS1 era graphics, very simple missions and a frankly poor soundtrack mean that there isn't much reason to play this now, although I'm sure it would have been a blast if I'd had a PS1 in the late 90s.

I haven't played AC:Infinity, which is essentially a multiplayer-focused remix of content from previous games with no story, or any of the mobile games. Which finally brings me to

ACE COMBAT 7 Review : based on completing the Xbox One X version a couple of times

Game Mechanics : Thankfully, a return to the classic AC6 flight model, all horrible Assault Horizon dogfight mode crap ditched. Unfortunately this means no non-fighter alternate mechanics to add variety, but I'd rather the dev team spent the time making a good core game anyway. Basic fighter maneuvers work and are relevant for most enemies, post-stall maneuvers have been added which are neat if not terribly useful (as per real life: executing them with more than one enemy nearby makes you a sitting duck for incoming missiles). AI is reasonable, wind has been added which is occasionally relevant as an additional control challenge. Other than the flight model, the feel is similar to AC4 due to no wingman commands and no allied support; you do have allies who very occasionally manage to kill something on their own, but it isn't tracked and doesn't happen often enough to make it feel like anyone other than you is actually fighting. Air to ground feels better due to the AA guns now firing a continuous stream of projectiles that you can jink around more reliably. Unfortunately, the supermaneuverable 'only let you hit us when we randomly forget to dodge' UAVs from AC6 are back and appear much more frequently, but have been toned down a bit to be less obnoxious; it isn't just pure luck whether you hit them, but it is still more 'pointer chasey' than fighting normal enemies. There is a missed opportunity with the clouds, which do offer an interesting mechanic of reduced visibility & tracking + icing risk and seem suited to cat-and-mouse extended dogfights, but the enforced pacing of the game (more on that below) means that you never really get time to play with this.

Aircraft variety is similar to AC4; there is one playable superplane, the X-02S (related to the X02 as the F-15E is to the F-15C); albeit with a excessive focus on endless variants of the SU-27. The difference in aircraft feel is a bit better than AC4/5 where even the A-10 seemed to be supersonic and everything had a similar ceiling. The weapon setup is odd; by default the cannon and the special weapons are underpowered and mostly useless, and you're better off just spamming standard missiles at everything. You unlock upgrade parts for aircraft and weapon stats and can upgrade the weapons to give you either an unreasonably powerful canon, or decent special weapons on a par with previous games (but not both unless you forgoe all stat upgrades). So far I haven't found any weapons as overpowered as the AC4 QAAMs, AC5 laser, AC0 burst missiles or AC6 multi-missiles; there is a TLS that you can upgrade to about equivalent to the AC0 Morgan version (i.e. much less powerful than the Falken's) and an railgun (aka the thing you never bothered with in AC6 because the multi-missiles were so much better). You still get a choice of only three predefined special weapons per aircraft which feels odd given that it's pretty random which aircraft can use the sci-fi weapons (there is a pulse laser as well as a beam laser, but it isn't as good as a fully ugpraded cannon). I assume this was done for aircraft differentiation, but it feels odd that the F-15E and SU-37 can use the sci-fi beam laser, but the F-22 has purely conventional weapons (the X-02S gets the QAAMs, although sadly not the classic AC4 version, and the EML).

Mission Design : Unfortunately quality mission design seems to be increasingly neglected in contemporary games; a lot of them feel like they were assembled by people who've read textbooks on 'gameplay loops' and 'reward models' and 'how to gamify anything in 10 days flat' but don't have a deep feel for games. For AC7 specifically it feels like concepts from previous games have been cribbed for both the design and the setting, but while the later is done intelligently, the former not so much. For example in AC5 there is a mission where you have to fly through a network of radar sites where the radar coverage circles (semi-realistically) increase at higher altitude. So you can fly higher and risk not being able to thread through the circles or fly lower and risk crashing into the terrain, and indeed vary your height through that part of the mission. For AC7 there is a mission where you have to thread through a radar network, but the height component is gone and you're mostly flying over ocean with no ships visible, so it's a mystery where all the little radar circles are coming from.

In general AC7 has a reasonable mix of gameplay tasks, but tends to be focused on doing one particular thing at a time, and frequently imposes extreme time pressure that both makes no narrative sense (why must we abandon the attack if we don't do enough damage in 8 minutes, there was no reference to operating at extreme range/fuel concerns or incoming enemies) and severly curtails the scope. For example there is an 'attack on the enemy capital' mission which takes place on literally the same map as the penultimate AC4 mission. There are roughly half as many targets which feels less realistic and climatic; compare to AC6 'retake the capital' mission which is twice as long, has about three times as many targets and has a reasonable number of allied forces which actually advance and can be interacted with. AC7 seems very reluctant to give you a 'spend half an hour systematically dismantling this enemy fortress or army' mission of the kind AC4/5/6 had, seemingly out of fear that the player will get bored. The last couple of missions are a Comona-style furball followed by an aerial battleship takedown that is essentially a smaller AC6 heavy command cruiser with the Arkbird style energy weapons, then a dogfight with two Falken drones followed by a short prefunctory tunnel segment (which feels really forced; why is that tunnel there when there is a perfectly serviceable bridge to the space elevator).

Story / Setting : The story is a grab bag of AC4 (Erusia is trying to take over the Usea continent again, you fight back from the brink) and AC5 (you are explicitly fighting for alt-US / Osea, you are set up and disgraced then come back in a new unit to save the day from Belkans who were developing superweapons and orchestrating the war) elements, with references to AC2 (the Falken drones) and AC0 (one ally fomerly from the World With No Boundaries anarchist group). The cutscenes like to follow unrelated female characters wandering about in the warzone, and there are aerial battleships frustrating the advance of your allies for most of the game, as per AC6. Overall writing quality is definitely better than AC6, but the profusion of AC history references is a bit forced; some are neat such as the reactivation of Stonehenge (on your side this time), others such as the use of the space launch mass driver to launch standard cargo flights (why?) and the cameo of President Harling. Contrast with AC5 which had things like an entire mission playfully referencing Die Hard, where the game mechanics and the writing combined to make it work well. That said the space elevator and drone elements are quite well done in both visual design and backstory.

Characterisation is pretty good given the time constraints, but the narrative suffers from the fact that the player character goes through three distinct squads over the course of the game; of your initial standard squadron, nearly everyone dies and then you are court martialed. Then you serve in a penal unit for a few missions, where your new allies and corrupt commander are barely characterised before they are shot down and you leave the unit (one comes with you). Finally you serve in a third squadron for the rest of the game. 20 missions isn't enough to pull this off when nearly all the cutscenes are devoted to mostly unrelated characters doing mostly unrelated things in the world; compared to the AC5 arc, the character discontinuity makes it feel disjointed and I didn't have the emotional response to losing allies (e.g. the three that get picked off by the main enemy ace) that I think the writers were going for.

Visuals : The engine is a major jump over AC6, primarily due to the realistic clouds (instead of simple volumetric fog and skyboxes) and HDR effects. All the bad parts of Assault Horizon (desaturation, drunken camera) are gone and the improved enemy destruction is retained, but at a sensible distance. If anything I would have liked more of the weather effects, there was a neat thunderstorm effect that appears in one level only, flying through rainclouds is a nice visual and audio effect but you don't have a reason to do it that much. Unfortuantely the console versions only do 1080p60 and still suffer from some pixelation on the ground textures, presumably due to lack of texture streaming / megatexturing; fortunately there is a PC version which can run in 4K and hopefully has better textures. Ground clutter is improved over AC6 but at the cost of some visible pop-in. Graphic design is generally good, but fewer standout visual elements than AC5/6 (on a par with AC4/0).

Audio : Sound effects are easily the best in the series; playing on a 7.1 system, the spatial audio cues are significantly better than Assault Horizon which was itself improved over all the classic games. If you have a proper home cinema system, this is a bigger bump in immersion than the graphical upgrades. Soundtrack is classic AC, mostly ochestral with some synth and a few operatic elements sprinkled in; not quite on an AC5 level but I'd rate it up with 4 & 6.

OVERALL : A solid entry in the series, good core gameplay and experience hobbled by spotty mission design, excessive time pressure, and a somewhat muddled story. For immersion, first-time playthrough and as an intro to the series for a contemporary gamer I'd put this in second place ahead of AC4 and behind AC5 (which retains its crown as the definitive AC game), however for replay value I think it will go between AC6 and AC0 due to AC6's missions having a more epic, less gimmicky feel. No idea on multiplayer; still don't feel the need to play this particular series competitively.